Until recently the oldest, unchallenged evidence of human hunting came from a 400,000-year-old site in Germany the evidence came from marks left by spears on horse bones - horses were clearly being speared and their flesh eaten. but new Evidence from ancient butchery site in Tanzania shows early man used complex hunting techniques to ambush and kill antelopes, gazelles, wildebeest and other large animals at least two million years ago.

The discovery -- by anthropologist Professor Henry Bunn of Wisconsin University -- pushes back the definitive date for the beginning of systematic human hunting by hundreds of thousands of years.

Two million years ago, our human ancestors were small-brained apemen previously many scientists assumed the meat they butchered and ate had been gathered from animals that had died from natural causes or had been left behind by lions, leopards and other carnivores - "We know that humans ate meat two million years ago," said Bunn, speaking at the European Society for the study of Human Evolution (ESHE). "What was not clear was the source of that meat.

However, we have compared the type of prey killed by lions and leopards today with the type of prey selected by humans in those days. This has shown that men and women could not have been taking kill from other animals or eating those that had died of natural causes. They were selecting and killing what they wanted."

Once our species got a taste for meat, it was provided with a dense, protein-rich source of energy. We no longer needed to invest internal resources on huge digestive tracts that were previously required to process vegetation and fruit, which are more difficult to digest.

This new, energy-rich resource was then diverted inside our bodies and used to fuel our growing brains. over the next two million years our crania grew, producing species of humans with increasingly large brains.Earliest tool was use 3.4 million years ago:

Researchers have found evidence that hominins - early human ancestors - used stone tools to cleave meat from animal bones more than 3.2 million years ago. That pushes back the earliest known tool use and meat-eating in such hominins by more than 800,000 years.

A new study suggests that Homo erectus, a precursor to modern humans, was using advanced toolmaking methods in East Africa 1.8 million years ago, at least 300,000 years earlier than previously thought. The study, recently published in Nature, raises new questions about where these tall and slender early humans originated and how they developed sophisticated tool-making technology.

Henry Bunn, anthropologist from Wisconsin University, speaking at the annual European Society for the study of Human Evolution meeting in Bordeaux this year, has suggested that the date that humans began hunting down large prey for food needs to be pushed back over a million and a half years after studying evidence of carcasses of antelopes, gazelles and wildebeest left behind by Homo habilis at a site in Tanzania. He said evidence there indicates that early man was hunting in an organized fashion some two million years ago.

New genetic findings suggest that early humans living about one million years ago were extremely close to extinction. The genetic evidence suggests that the effective population—an indicator of genetic diversity—of early human species back then, including Homo erectus, H. ergaster and archaic H. sapiens, was about 18,500 individuals (it is thought that modern humans evolved from H. erectus), says Lynn Jorde, a human geneticist at the University of Utah in Salt Lake City. That figure translates into a total population of 55,500 individuals, tops.